Duty Cycle Generator and Power Converter

A power converter for converting an input voltage to an output voltage, comprising:

• a duty cycle generator for generating a duty cycle signal, comprising:
• a first inverter coupled to a clock signal for inverting the clock signal;
• a second inverter cascaded to the first inverter for outputting the clock signal;
• a signal protection unit including an input terminal coupled to the duty cycle signal for generating a break pulse to generate a protected duty cycle signal;
• a comparator including a positive input terminal coupled to a comparison signal of the power converter and a negative input terminal coupled to a triangle-wave signal for comparing the triangle-wave signal with the comparison signal to generate a comparison result;
• a NOR gate including a first input terminal coupled to the comparison result, and a second input terminal coupled to an output terminal of the signal protection unit for generating a reset signal according to the comparison result and the protected duty cycle signal;
• an SR-latch including a set input terminal coupled to an output terminal of the second inverter, a reset input terminal coupled to an output terminal of the NOR gate, and an output terminal for outputting a turn-on signal according to the clock signal and the reset signal;
• and
• an AND gate including a first input terminal coupled to the output terminal of the SR-latch, and a second input terminal coupled to the output terminal of the first inverter and the input terminal of the second inverter for generating the duty cycle signal according to the inverted clock signal and the turn-on signal;
• a drive stage circuit coupled to an output terminal of the duty cycle generator for outputting a switch signal according to the duty cycle signal;
• an output stage circuit coupled to an output terminal of the drive stage circuit for generating the output voltage according to the switch signal;
• and
• a feedback circuit coupled between the output stage circuit and the duty cycle generator for outputting the comparison signal to the duty cycle generator according to the output voltage.